The instant invention relates to a cassette for feeding paper sheets to be fed seriatim therefrom, and more particularly to such a cassette which allows the use of various lengths of paper in an electrophotocopying machine without requiring the changing of cassettes.
The transfer paper for transfer type copying devices, and the photosensitive paper used in electrofax systems, as well as the printing paper used in simple printers are considered as cut sheets. It is common practice to automatically feed such sheets by positioning them in a cassette and then loading the cassette into the unit. Some of the prior art cassettes include free floating corner separators which exert a downward pressure on the stack of sheets being fed equal only to their own weight, and a paper elevating plate which can be spring biased upwardly against a feed roller so that the top sheet of the stack of sheets is always fed from the same height. An example of the foregoing type of cassette can be found in U.S. Pat. No. 3,919,972, issued Nov. 18, 1975.
With prior art cassettes, whenever it is desired to provide a machine such as a photocopier with more than one size paper, a number of cassettes corresponding to the number of different sized sheets employed must be used. The instant invention overcomes this problem by providing a cassette which includes the latest advance of free floating corner separators and an upwardly biased paper elevating plate and which can accommodate many different sizes of paper. The advantage of the instant invention is that when a machine operator desires to change the size of the paper, it is only necessary to raise the cover of the cassette, remove the paper already in the cassette, and insert the desired paper into the cassette; there is no need for the operator to move any other levers or parts of the cassette independent from the cassette cover, as the upwardly biased paper elevating plate is automatically depressed by the cover of the cassette being raised.